The Scottish Government has rejected a Westminster offer to resolve the Brexit "power grab" impasse amid claims that Nicola Sturgeon overruled her minister Mike Russell to "kibosh" the deal.

MSPs were told at Holyrood today that the Scottish Government cannot accept the latest proposed "political deal" on offer from UK ministers. It comes as the Welsh Government - which had similar "power grab" concerns - today accepted the same deal offered by UK ministers caliming it would “protect devolution.”

Opposition MSPs hit out insisting that "it is Scotland alone" which is blocking a deal and suggested the SNP's approach is down to its desire for a second independence referendum. Mr Russell insisted there was "no crack" in the Scottish Government's position.

Westminster's EU Withdrawal Bill will continue to “enable the powers of the Scottish Parliament to be constrained” unless Clause 11 of the UK Bill is either withdrawn or amended, Mr Russell said in a statement to MSPs today..

The row centres on powers being repatriated from Brussels to the UK after Brexit and claims that powers which should come to Holyrood in line with the devolution agreement are being appropriated by Westminster.

Nicola Sturgeon has written to Theresa May to reject the latest UK Brexit offer

The First Minister has today written to the Prime Minister setting out the remaining concerns.

“We have given them serious and respectful consideration but we as a government are absolutely and unanimously clear that we cannot support any proposal that would without the agreement of the Scottish Parliament," he said.

“And the UK Government’s latest proposals continue to give Westminster the power to prevent the Scottish Parliament from passing laws in certain devolved policy areas and while we expect the amendments to include the addition of a sunset clause the restrictions on our use of these powers would last for up to seven years.

"While any constraint placed on the UK Government will be purely voluntary.

“The effect of the UK Government’s latest proposal remains this: the Scottish Parliament’s powers could be restricted without consent. This is not something the Scottish Government could recommend the Parliament approves."

Mr Russell told MSPs that a deal can be struck if clause 11 is removed or alternatively if changes were agreed to the effect that any move to allow Westminster to legislate in devolved areas is done when that is agreed by the Scottish Parliament.

The UK Government Cabinet Secretary David Lidington voiced his frustration at the Scottish Government’s refusal to sign up and urged a rethink.

He said: “It is disappointing that the Scottish Government have not yet felt able to add their agreement to the new amendments that Ministers and officials on all sides have been working on very hard over recent weeks. I thank them for that effort and hope that they may still reconsider their position.

“All governments agree that it would be best for all parts of the UK if we had an agreed way forward on the EU Withdrawal Bill.”

The Scottish Tories’ Brexit spokesman Adam Tomkins insisted that the UK Government has listened to concerns of the Scottish Parliament and "has come forward with a new offer which it will publish tomorrow."

But he added: "For narrow political reasons, the SNP once again says no.

"This it seems has nothing to do with the matter at hand and everything to do with their obsession with a second referendum on independence."

And he added: "Isn't the case that he (Mr Russell) was in fact prepared to sign up to this deal today but was overruled last week by the First Minister? Isn't the case when it comes to consent, he was prepared to give it, but she refused?"

Labour's Brexit spokesman Neil Findlay also suggested a split between Ms Sturgeon and the Brexit minister pointing to the "body language, but lack of real language" between the pair in the chamber.

"That would suggest that there was potentially a deal to be struck and the Cabinet Secretary wanted to sign it, but it' been kiboshed by the First Minister," he said.

But Mr Russell hit back: "I can assure you that the relationship with the First Minister seems fine to me and I think it seems fine to her too."

He insisted that the lack of consent for the Scottish Parliament was a roadblock for all ministers.

"I stand four square behind that position - as I indicated so does the entire Government, there's no crack in that."